Many aircraft components manufactured with composite materials use panels stiffened with stringers whose designs have zones of intersection or interference with other structural elements of the component.
So for example, in the wing of an aircraft, the reinforcing stringers of the skin panels are crossed by the ribs and the ends of some of them may be arranged in zones close to the spars creating potential interferences.
If the ends of the stringers (“run-outs”) are configured with no shape variation the problem arises that, in those zones of the panel that are not stiffened by stringers due to the impracticability of extending some of them on account of the potential interference or intersection with a rib or spar, we find some zones in which it is necessary to increase the thickness of the panel and consequently its weight. Furthermore, in the termination zone of a stringer a modification occurs in the load distribution between the panel and the stringer which causes certain problems.
To overcome these problems there are several known proposals in the prior art to configure the ends of the stringers used in stiffened panels such as those mentioned. WO 2008/132498 describes a solution to the problem of load distribution and in the detailed description of the invention we will mention proposed configurations of the ends of the stringers to reduce the unstiffened zones of the panel that have various drawbacks which this invention is intended to overcome.